The application uses a A star algorithm to traverse the search space. 
In this case is a node of the search tree a represention of a state which can appear in the game.
It leads faster to a solution if the branches gets evaluated.
The end of a branch is reached when no moves possible which we did not tried bevor or the search depth is at the limit of 1000. 

\begin{figure}[htbp]
  \centering
  \fbox{
    \includegraphics[width=60mm]{bisearch.png} 
  }
  \caption{Searchtree in forward and reverse direction}
  \label{pic:bisearch}
\end{figure}





%We use A star to traverse the search space. 
%What is a node\\
%Evaluation for the branches \\
%Terminating a  branch when no more nodes\\

%The search depth is limited to 1000 moves.
%\includegraphics[width=60mm]{bisearch.png} 